1. Field of the Invention
The present invention relates to a fuel cell formed by stacking a membrane electrode assembly and separators. The membrane electrode assembly includes a pair of electrodes, and an electrolyte membrane interposed between the electrodes. Further, the present invention relates a method of producing the fuel cell.
2. Description of the Related Art
For example, a solid polymer electrolyte fuel cell employs a membrane electrode assembly (MEA) which includes an anode, a cathode, and an electrolyte membrane interposed between the anode and the cathode. The electrolyte membrane is a polymer ion exchange membrane. The membrane electrode assembly and separators sandwiching the membrane electrode assembly make up a unit cell. In use, generally, a predetermined number of unit cells of this type are stacked together to form a fuel cell stack.
Normally, several tens to hundreds of fuel cells are stacked together to form a fuel cell stack. It is necessary to accurately position the components of the fuel cell and stack the fuel cells in alignment with each other accurately. In this regard, for example, a fuel cell as disclosed in Japanese Laid-Open Patent Publication No. 2004-241208 is known.
In the fuel cell, a plurality of metal clip members are provided for supporting the outer circumferences of the first and second separators at a plurality of positions. Each of the metal clip members includes a side plate and first and second tongues folded at ends of the side plate for holding the outer circumferences of the first and second separators. The first and second tongues are longer than the side plate, and have elasticity.
In the fuel cell, operation of attaching the metal clip members at the plurality of positions is required for each of the fuel cells. Therefore, the operation of attaching the metal clip members is laborious. In particular, at the time of assembling the fuel cell stack by stacking several hundreds of fuel cells, considerable time and labor are required for the operation. Therefore, the assembling operation cannot be performed efficiently.
Further, when it is necessary to analyze the fuel cell, or when it is necessary to replace parts of the fuel cell, the fuel cell needs to be disassembled. At this time, metal clip members need to be detached, and this detaching operation is considerably laborious.